Field of the Invention
The present invention relates to a heat exchanger, and more particularly, to a heat exchanger which heat-exchanges working fluids having different temperatures.
Description of Related Art
In general, an air conditioning system of a vehicle maintains a temperature inside the vehicle at an appropriate temperature regardless of a change of an outside temperature and maintains a pleasant indoor environment.
The air conditioning system includes a compressor compressing a coolant, a condenser condensing the coolant compressed by the compressor, an expansion valve rapidly expanding the coolant condensed by the condenser and liquefied, and an evaporator cooling air blown inside a vehicle in which the air conditioning system is installed, by using evaporative latent heat of the coolant while evaporating the coolant expanded by the expansion valve, as main constituent elements.
The air conditioning system is operated according to a general cooling cycle, and the coolant is continuously phase-changed from a high temperature and high pressure liquid state to a low temperature and low pressure gas state while sequentially and repeatedly circulating through the constituent elements, so that a cooling process is performed.
Here, the high temperature and high pressure liquid coolant is mutually heat-exchanged with the low temperature and low pressure gas coolant through the heat exchanger having a dual pipe structure installed in an air conditioner pipe, so that the coolant is supercooled.
However, the air conditioning system for a vehicle in the related art has a structure in which the heat exchanger supercools the coolant condensed by the condenser again, so that a coolant flow is complex, and thus there is a problem in that a pressure drop inside inlet and outlet pipes of the condenser is frequently incurred.
Further, the condenser has a limited size, and an internal space of an engine room is narrow and small and thus a length of the pipe of the air conditioner through which the coolant moves is limited, so that a minimum required length for reducing a temperature of the coolant to a required temperature is not satisfied, and thus a coefficient of performance (COP) that is a coefficient of cooling performance compared to consumed power of the compressor is decreased, thereby degrading entire cooling performance and efficiency of the air conditioning system.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.